1. Field of the Invention
The present invention is a resealable closure for containers. More particularly the present invention is a resealable closure for plastic containers which is adapted to be opened and closed with one hand.
2. Related Art
Containers for holding and dispensing fluids such as drinks, motor oils, detergents, shampoos, household products, and free flowing solids, for example free-flowing powders, preferably have resealable closures. Resealable closures are desirable because they allow the closure to be replaced on the container if all of the container contents have not been dispensed. Thus, such containers can contain more than a single use amount of material, resulting in decreased packaging costs. Another advantage of resealability is the ability to reuse containers.
Two common and well known types of resealable closures are threaded closures and friction fit or snap-fit closures. Threaded closures have been in existence for many years. In a threaded closure, a finish on the container, for example at the neck of a container, has external threads. A cap, or closure, is adapted to engage the threads of the finish for attachment to the container. This can be, for example, a projection in the closure or matching threads on a corresponding interior surface of the closure. In a friction fit or snap-fit closure system, the finish comprises an externally projecting ring that engages an inward facing projection on the closure. When the closure is forced onto the finish, the inward facing ring on the closure is forced to a position below the externally projecting ring on the finish. As a result, the closure stays on the container unless sufficient force is applied to push the inward facing ring back over the externally projecting ring on the finish. This arrangement, which requires the use of resilient material for the externally projecting ring on the finish and/or the inward facing ring on the closure, has been facilitated by the use of plastic bottles.
These two closure systems suffer several drawbacks. For example, two hands are often required to open and reseal the container. Furthermore, the use of separate pieces can result in the two components being separated and the closure lost. One solution to this problem is the use of closures that are connected to the finish by a hinge. However, even in this case, opening and resealing may be cumbersome.
Another solution to the problems encountered with threaded and friction fit closures is a closure system that opens and closes by sliding. These types of resealable closures are commonly used on bottles manufactured for “sports drinks” (i.e., beverages that are intended to replace electrolytes lost from the body though physical activity) and on water bottles. Water bottles can be containers specifically manufactured to contain water to be sold as a commodity and empty bottles that are designed for reuse and may be adapted for attachment to a holder on a bicycle.
In these types of closure systems, the finish of the bottle contains a thread. The closure generally consists of two pieces, a base and a cap. The base has threads that allow it to be attached to the bottle. Some of these systems can also use a friction fit or snap-fit arrangement to attach the base to the finish instead of a thread. On the other end of the base, there is a post surrounded by openings through which the product can flow. The cap has a receptacle for the post and is designed to slide up and down on the base. Typically, the cap resembles a column with a cone attached to the top. The base of the cone has a larger diameter than the column to create a mushroom-like appearance. The extra width of the cone provides a grip point on the cap for the user to grab in order to slide the cap up and down. When the cap is pushed toward the bottle, the receptacle tightly engages the post of the base and creates a seal. When the cap is moved up, the receptacle moves away from the post and the product can flow out the openings in the base, around the post and out the now open receptacle.
Although these types of systems provide resealabilty, there are several disadvantages. First, the use of a separate base and bottle can undesirably add manufacturing costs. Many of the current systems of this type require a base that is approximately the same size as a typical closure for these bottles. The cap is an additional piece at an additional cost. An even greater disadvantage of such systems is that two hands are generally required to open the container, although many users also use their teeth to grip the cone of the cap and open the bottle and then push it against some solid object to reclose the cap. The use of one's teeth to open and close the cap can result in wear on the cap. Further, although this is suitable for beverages or other edible products, a user is unlikely to use their teeth to open a cap if the container contained motor oil, detergent or some toxic substance, and two hands are therefore required.
What is needed is a closure system that avoids these disadvantages in the art. In particular, there remains a need for resealable closure systems that are simple and require a limited number of easily formed pieces in order to be cost-effective to manufacture. There is also a need for closure systems that can be opened and closed with one hand while gripping the container.